I was using Ubuntu 20.04 with g++ updated to g++15.1 (compiled from source)

I changed to Ubuntu 25.04 and g++15.0 (from ubuntu's ppa)

I checked a c++config.h file where _GLIBCXX_HAVE_IS_CONSTANT_EVALUATED is defined now there are test for more recent version of c++ which seem to modify it depending on latest version of c++.

So basically, everything must be very recent to work.